Human growth hormone formulations known in the art are all lyophilized preparations requiring reconstitution. Per vial, Protropin.RTM. hGH consists of 5 mg hGH, 40 mg mannitol, 0.1 mg monobasic sodium phosphate, 1.6 mg dibasic sodium phosphate, reconstituted to pH 7.8 (Physician's Desk Reference, Medical Economics Co., Orawell, N.J., p. 1049, 1992). Per vial, Humatrope.RTM. hGH consists of 5 mg hGH, 25 mg mannitol, 5 mg glycine, 1.13 mg dibasic sodium phosphate, reconstituted to pH 7.5 (Physician's Desk Reference, p. 1266, 1992).
For a general review for growth hormone formulations, see Pearlman et al., Current Communications in Molecular Biology, eds. D. Marshak and D. Liu, pp. 23-30, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989. Other publications of interest regarding stabilization of proteins are as follows.
U.S. Pat. No. 4,297,344 discloses stabilization of coagulation factors II and VIII, antithrombin III, and plasminogen against heat by adding selected amino acids such as glycine, alanine, hydroxyproline, glutamine, and aminobutyric acid, and a carbohydrate such as a monosaccharide, an oligosaccharide, or a sugar alcohol.
U.S. Pat. No. 4,783,441 discloses a method for the prevention of denaturation of proteins such as insulin in aqueous solution at interfaces by the addition of up to 500 ppm surface-active substances comprising a chain of alternating, weakly hydrophilic and weakly hydrophobic zones at pH 6.8-8.0.
U.S. Pat. No. 4,812,557 discloses a method of stabilization of interleukin-2 using human serum albumin.
European Patent Application Publication No. 0 303 746 discloses stabilization of growth promoting hormones with polyols consisting of non-reducing sugars, sugar alcohols, sugar acids, pentaerythritol, lactose, water-soluble dextrans, and Ficoll, amino acids, polymers of amino acids having a charged side group at physiological pH, and choline salts.
European Patent Application Publication No. 0 211 601 discloses the stabilization of growth promoting hormones in a gel matrix formed by a block copolymer containing polyoxyethylene-polyoxypropylene units and having an average molecular weight of about 1,100 to about 40,000.
European Patent Application Publication No. 0 193 917 discloses a biologically active composition for slow release characterized by a water solution of a complex between a protein and a carbohydrate.
Australian Patent Application No. AU-A-30771/89 discloses stabilization of growth hormone using glycine and mannitol.
U.S. Pat. No. 5,096,885 (which is not prior art) discloses a formulation of hGH for lyophilization containing glycine, mannitol, a non-ionic surfactant, and a buffer. The instant invention provides an unexpectedly stabilized aqueous formulation in the absence of glycine.
hGH undergoes several degradative pathways, especially deamidation, aggregation, clipping of the peptide backbone, and oxidation of methionine residues. Many of these reactions can be slowed significantly by removal of water from the protein. However, the development of an aqueous formulation for hGH has the advantages of eliminating reconstitution errors, thereby increasing dosing accuracy, as well as simplifying the use of the product clinically, thereby increasing patient compliance. Thus, it is an objective of this invention to provide an aqueous hGH formulation which provides acceptable control of degradation products, is stable to vigorous agitation (which induces aggregation), and is resistant to microbial contamination (which allows multiple use packaging).